The related art is discussed, using the packaging of a MEMS microphone component as an example, without limiting the present invention to this particular application case.
It is known that substrate-based housings may be used for the packaging of MEMS microphone components. In this packaging variant, the microphone chip is mounted onto a planar component support referred to as a substrate, electrically contacted, and housed with a cover, using chip-on-board (COB) technology. If the sound entrance port is situated in the cover of the housing, then the back-side volume is limited, as a rule, to the chip cavity, which means that the microphone performance is also limited. As an alternative to that, the sound entrance port may be formed under the microphone chip, in the component support. In this case, the entire cavity in the housing is available as back-side volume, which allows an increase in performance to be obtained.
Regardless of application-specific requirements, the known packaging concept has proven to be problematic in two different respects.
Thus, in practice, mechanical stresses often occur in the sensitive structure of the MEMS component, which are dependent on mounting and may be attributed to different thermal expansion coefficients of, on one hand, the MEMS component and, on the other hand, the component support. Such mechanical stresses always affect the performance reliability of a MEMS component.
Since the known packaging concept provides side-by-side mounting of the components on the planar component support, the footprint of the assembly also increases with the number of components inside the housing. However, increasing the area of the assembly always leads to an increase in production costs, as well.